1. Field of the Invention
This invention relates to a method and apparatus of mounting an elastic annular member, and for automatically fitting an elastically-deformable elastic annular member having an inner diameter which is smaller than the outer diameter of a workpiece, such as a shaft member or the like, on the workpiece.
2. Description of the Prior Art
In some conventional apparatuses for mounting an elastically-deformable elastic annular member, such as an O-ring or the like, on a workpiece, such as a shaft member or the like, a leading-end portion of the workpiece in which the elastic annular member is to be mounted is covered with a cap whose outer surface has the shape of a cone, the elastic annular member having an inherent inner diameter smaller than the outer diameter of the work is fitted on the cap, and the elastic annular member is fitted on the workpiece by enlarging the inner diameter of the elastic annular member along the outer surface of the cap by pushing down the elastic annular member toward the workpiece with a pushing rod having a plurality of pawls (see Japanese Utility Model Application Public Disclosure (Kokai) Nos. 58-70835 (1983) and 57-122323 (1972)).
However, in the above-described conventional approach, after covering the workpiece with the conical cap for enlarging the inherent inner diameter of the elastic annular member to an inner diameter greater than the outer diameter of the workpiece, the elastic annular member is pushed down toward the workpiece by the pushing rod having the plurality of pawls. Hence, a complicated apparatus is needed, and time is needed for attaching and detaching the conical cap, resulting in a long cycle time.